The Role of Rainfed Agriculture in the Future of Global Food Production

EPTD Discussion Papers contain preliminary material and research results, and are circulated prior to a full peer review in order to stimulate discussion and critical comment. It is expected that most Discussion Papers will eventually be published in some other form, and that their content may also be revised. ACKNOWLEDGMENTS The authors would like to thank Susanne Neubert and John Pender for helpful comments on an earlier draft of this paper. i EXECUTIVE SUMMARY This paper examines future prospects for rainfed cereal production, and its importance in the evolving global food system. The IMPACT-WATER integrated water-food modeling framework developed at IFPRI is applied to assess the current situation and plausible future options of irrigation water supply and food security, primarily on a global scale. This model simulates the relationships among water availability and demand, food supply and demand, international food prices, and trade at regional and global levels. Globally, 69 percent of all cereal area is rainfed, including 40 percent of rice, 66 percent of wheat, 82 percent of maize and 86 percent of other coarse grains. Worldwide, rainfed cereal yield is about 2.2 metric tons per hectare, which is about 65 percent of the irrigated yield (3.5 metric tons per hectare). Rainfed areas currently account for 58 percent of world cereal production. The baseline projection from the IMPACT-WATER model—which incorporates our best estimates of the policy, investment, technological, and behavioral parameters driving the food and water sectors—shows that rainfed agriculture will continue to play a major role in cereal production, accounting for about one-half of the increase in cereal production between 1995 and 2021-25. The importance of rainfed cereal production is partly due to the dominance of rainfed agriculture in developed countries. More than 80 percent of cereal area in developed countries is rainfed, much of which is highly productive maize and wheat land such as that in the Midwestern United States and parts of Europe. The average rainfed cereal yield in developed countries was 3.2 metric tons per hectare in 1995, virtually as high as irrigated cereal yields in developing countries. ii Rainfed cereal yields in developed countries are projected to grow to 3.9 metric tons per hectare by 2021-25. Irrigation is relatively more important in cereal production in developing countries, with nearly 60 percent of future cereal production in developing countries coming from irrigated areas. However, rainfed agriculture remains important in developing countries as well. Rainfed yields …